via.c

h内核

/*
 *	6522 Versatile Interface Adapter (VIA)
 *
 *	There are two of these on the Mac II. Some IRQ's are vectored
 *	via them as are assorted bits and bobs - eg RTC, ADB.
 *
 * CSA: Motorola seems to have removed documentation on the 6522 from
 * their web site; try
 *     http://nerini.drf.com/vectrex/other/text/chips/6522/
 *     http://www.zymurgy.net/classic/vic20/vicdet1.htm
 * and
 *     http://193.23.168.87/mikro_laborversuche/via_iobaustein/via6522_1.html
 * for info.  A full-text web search on 6522 AND VIA will probably also
 * net some usefulness. <[e-mail]> 20apr1999
 *
 * PRAM/RTC access algorithms are from the NetBSD RTC toolkit version 1.08b
 * by Erik Vogan and adapted to Linux by Joshua M. Thompson ([e-mail])
 *
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/ide.h>

#include <asm/traps.h>
#include <asm/bootinfo.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/machw.h>
#include <asm/mac_via.h>
#include <asm/mac_psc.h>

volatile __u8 *via1, *via2;
#if 0
/* See note in mac_via.h about how this is possibly not useful */
volatile long *via_memory_bogon=(long *)&via_memory_bogon;
#endif
int  rbv_present,via_alt_mapping;
__u8 rbv_clear;

/*
 * Globals for accessing the VIA chip registers without having to
 * check if we're hitting a real VIA or an RBV. Normally you could
 * just hit the combined register (ie, vIER|rIER) but that seems to
 * break on AV Macs...probably because they actually decode more than
 * eight address bits. Why can't Apple engineers at least be
 * _consistently_ lazy?                          - 1999-05-21 (jmt)
 */

static int gIER,gIFR,gBufA,gBufB;

/*
 * Timer defs.
 */

#define TICK_SIZE		10000
#define MAC_CLOCK_TICK		(783300/HZ)		/* ticks per HZ */
#define MAC_CLOCK_LOW		(MAC_CLOCK_TICK&0xFF)
#define MAC_CLOCK_HIGH		(MAC_CLOCK_TICK>>8)

static int  nubus_active;

void via_debug_dump(void);
irqreturn_t via1_irq(int, void *, struct pt_regs *);
irqreturn_t via2_irq(int, void *, struct pt_regs *);
irqreturn_t via_nubus_irq(int, void *, struct pt_regs *);
void via_irq_enable(int irq);
void via_irq_disable(int irq);
void via_irq_clear(int irq);

extern irqreturn_t mac_bang(int, void *, struct pt_regs *);
extern irqreturn_t mac_scc_dispatch(int, void *, struct pt_regs *);
extern int oss_present;

/*
 * Initialize the VIAs
 *
 * First we figure out where they actually _are_ as well as what type of
 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
 * Then we pretty much clear them out and disable all IRQ sources.
 *
 * Note: the OSS is actually "detected" here and not in oss_init(). It just
 *	 seems more logical to do it here since via_init() needs to know
 *	 these things anyways.
 */

void __init via_init(void)
{
	switch(macintosh_config->via_type) {

		/* IIci, IIsi, IIvx, IIvi (P6xx), LC series */

		case MAC_VIA_IIci:
			via1 = (void *) VIA1_BASE;
			if (macintosh_config->ident == MAC_MODEL_IIFX) {
				via2 = NULL;
				rbv_present = 0;
				oss_present = 1;
			} else {
				via2 = (void *) RBV_BASE;
				rbv_present = 1;
				oss_present = 0;
			}
			if (macintosh_config->ident == MAC_MODEL_LCIII) {
				rbv_clear = 0x00;
			} else {
				/* on most RBVs (& unlike the VIAs), you   */
				/* need to set bit 7 when you write to IFR */
				/* in order for your clear to occur.       */
				rbv_clear = 0x80;
			}
			gIER = rIER;
			gIFR = rIFR;
			gBufA = rSIFR;
			gBufB = rBufB;
			break;

		/* Quadra and early MacIIs agree on the VIA locations */

		case MAC_VIA_QUADRA:
		case MAC_VIA_II:
			via1 = (void *) VIA1_BASE;
			via2 = (void *) VIA2_BASE;
			rbv_present = 0;
			oss_present = 0;
			rbv_clear = 0x00;
			gIER = vIER;
			gIFR = vIFR;
			gBufA = vBufA;
			gBufB = vBufB;
			break;
		default:
			panic("UNKNOWN VIA TYPE");
	}

	printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);

	printk(KERN_INFO "VIA2 at %p is ", via2);
	if (rbv_present) {
		printk(KERN_INFO "an RBV\n");
	} else if (oss_present) {
		printk(KERN_INFO "an OSS\n");
	} else {
		printk(KERN_INFO "a 6522 or clone\n");
	}

#ifdef DEBUG_VIA
	via_debug_dump();
#endif

	/*
	 * Shut down all IRQ sources, reset the timers, and
	 * kill the timer latch on VIA1.
	 */

	via1[vIER] = 0x7F;
	via1[vIFR] = 0x7F;
	via1[vT1LL] = 0;
	via1[vT1LH] = 0;
	via1[vT1CL] = 0;
	via1[vT1CH] = 0;
	via1[vT2CL] = 0;
	via1[vT2CH] = 0;
	via1[vACR] &= 0x3F;

	/*
	 * SE/30: disable video IRQ
	 * XXX: testing for SE/30 VBL
	 */

	if (macintosh_config->ident == MAC_MODEL_SE30) {
		via1[vDirB] |= 0x40;
		via1[vBufB] |= 0x40;
	}

	/*
	 * Set the RTC bits to a known state: all lines to outputs and
	 * RTC disabled (yes that's 0 to enable and 1 to disable).
	 */

	via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
	via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);

	/* Everything below this point is VIA2/RBV only... */

	if (oss_present) return;

#if 1
	/* Some machines support an alternate IRQ mapping that spreads  */
	/* Ethernet and Sound out to their own autolevel IRQs and moves */
	/* VIA1 to level 6. A/UX uses this mapping and we do too.  Note */
	/* that the IIfx emulates this alternate mapping using the OSS. */

	switch(macintosh_config->ident) {
		case MAC_MODEL_C610:
		case MAC_MODEL_Q610:
		case MAC_MODEL_C650:
		case MAC_MODEL_Q650:
		case MAC_MODEL_Q700:
		case MAC_MODEL_Q800:
		case MAC_MODEL_Q900:
		case MAC_MODEL_Q950:
			via_alt_mapping = 1;
			via1[vDirB] |= 0x40;
			via1[vBufB] &= ~0x40;
			break;
		default:
			via_alt_mapping = 0;
			break;
	}
#else
	/* The alernate IRQ mapping seems to just not work. Anyone with a   */
	/* supported machine is welcome to take a stab at fixing it. It     */
	/* _should_ work on the following Quadras: 610,650,700,800,900,950  */
	/*                                               - 1999-06-12 (jmt) */

	via_alt_mapping = 0;
#endif

	/*
	 * Now initialize VIA2. For RBV we just kill all interrupts;
	 * for a regular VIA we also reset the timers and stuff.
	 */

	via2[gIER] = 0x7F;
	via2[gIFR] = 0x7F | rbv_clear;
	if (!rbv_present) {
		via2[vT1LL] = 0;
		via2[vT1LH] = 0;
		via2[vT1CL] = 0;
		via2[vT1CH] = 0;
		via2[vT2CL] = 0;
		via2[vT2CH] = 0;
		via2[vACR] &= 0x3F;
	}
}

/*
 * Start the 100 Hz clock
 */

void __init via_init_clock(irqreturn_t (*func)(int, void *, struct pt_regs *))
{
	via1[vACR] |= 0x40;
	via1[vT1LL] = MAC_CLOCK_LOW;
	via1[vT1LH] = MAC_CLOCK_HIGH;
	via1[vT1CL] = MAC_CLOCK_LOW;
	via1[vT1CH] = MAC_CLOCK_HIGH;

	request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func);
}

/*
 * Register the interrupt dispatchers for VIA or RBV machines only.
 */

void __init via_register_interrupts(void)
{
	if (via_alt_mapping) {
		cpu_request_irq(IRQ_AUTO_1, via1_irq,
				IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
				(void *) via1);
		cpu_request_irq(IRQ_AUTO_6, via1_irq,
				IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
				(void *) via1);
	} else {
		cpu_request_irq(IRQ_AUTO_1, via1_irq,
				IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
				(void *) via1);
#if 0 /* interferes with serial on some machines */
		if (!psc_present) {
			cpu_request_irq(IRQ_AUTO_6, mac_bang, IRQ_FLG_LOCK,
					"Off Switch", mac_bang);
		}
#endif
	}
	cpu_request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
			"via2", (void *) via2);
	if (!psc_present) {
		cpu_request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
				"scc", mac_scc_dispatch);
	}
	request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
			"nubus", (void *) via2);
}

/*
 * Debugging dump, used in various places to see what's going on.
 */

void via_debug_dump(void)
{
	printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
		(uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
	printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
		(uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
	if (oss_present) {
		printk(KERN_DEBUG "VIA2: <OSS>\n");
	} else if (rbv_present) {
		printk(KERN_DEBUG "VIA2:  IFR = 0x%02X  IER = 0x%02X\n",
			(uint) via2[rIFR], (uint) via2[rIER]);
		printk(KERN_DEBUG "      SIFR = 0x%02X SIER = 0x%02X\n",
			(uint) via2[rSIFR], (uint) via2[rSIER]);
	} else {
		printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
			(uint) via2[vDirA], (uint) via2[vDirB],
			(uint) via2[vACR]);